一、引言众所周知,新生儿死亡率随同监护技术的改进出现下降,但极低出生体重(<1500克)新生儿的医疗费用仍然超出其经济效益。Walker 等的研究表明,900克以下出生体重新生儿监护病室费用很高,但生存率很低。Boyle 等报告,1000—1499克出生体重新生儿监护病室的效果远较500—999克出生 I. INTRODUCTION It is well-known that neonatal mortality declines along with improvements in monitoring techniques, but medical costs for newborns with extremely low birth weight (<1500 g) still exceed their economic benefits. Walker et al.’s study showed that newborn birth units with a birth weight of less than 900 grams are expensive, but the survival rate is low. Boyle et al. reported that the effect of 1000-1499 g birth weight neonatal care unit was much higher than 500-999 g.